Radiant energy receiver



w. R. F OLYE RADIANT ENERGY RECEIVER June 8,, 1948;

' Filed March 15, 1944 INVENTOR. William/R. Poye BY g A T TOP/V5) Patented June 8, 1948 RADIANT ENERGY RECEIVER 7 William R. Polyc, River Edge, N. 'J., assignor to Bendix Aviation Corporation, Teterboro, N. J a corporation of Delaware Application March 13, 1944, Serial No. 526,244

This invention relates generally to radiant energy devices and more particularly to radiant energy receiver cells of the type utilizing a material adapted for releasing a gas flow within the cell in response to radiant energy.

A well known method of detecting the presence of radiant energy is to allow the radiant energy to enter a closed chamber containing finely divided carbonized material having gas adsorbing characteristics whereby the material releases gas to flow within the chamber. It has been, heretofore, proposed to utilize the resulting increase in gas pressure within the chamber to cause mechanical movement of some suitable expedient in such a, way that the pressure changes are transformed into electrical changes. A serious disadvantage, however, in the use of known systems is that they are necessarily aifected by mechanical vibrations in that they must depend upon movement of bodies having considerable inertia.

An object of the present invention, therefore, is to provide a novel receiver cell responsive to radiant energy and one which will remain substantially unaffected by mechanical vibration.

Another object of the invention is to provide a novel radiant energy receiver cell having no moving parts whereby errors due to accelerations, vibrations or shocks are eliminated.

A further object is to provide a novel radiant energy receiver cell utilizing a heated resistor element and a material which in response to radiant energy emits a gas flow n the resistor to vary the value thereof, the resistor being arranged in a suitable and normally balanced electrical circuit whereby in response to the gas flow the circuit becomes unbalanced.

The above and further objects and novel features of the invention will more fully appear from the following detailed description when the same is read in connectio with the accompanying drawings. It is to be expressly understood, however, that the drawings are for purposes of illustration only and are not intended as a definition of the limits of the invention.

In the drawings, wherein like reference characters refer to like parts throughout the several views;

Figure 1 is a side elevation view in section of the novel radiant energy receiver cell of the present invention;

Figure 2 is a view taken substantially along line 2--2 of Figure 1;

Figure 3 represents one form of measuring circuit adapted for use with the receiver cell of Figure 1; and

13 Claims. (Cl. 250-833) Figure 4 represents another form of an elec trical measuring circuit adapted for use with the receiver cell of Figure 1.

The principle utilized in perfecting the present invention is that the resistance of a current conductor will vary as the temperature of the conductor is varied, i. e., the resistance to current flow increases with increase in temperature and decreases with a decrease in temperature. The conductor herein is in the form of a coil element mounted in such a manner that gas fiow released by a radiant energy responsive substance impinges upon the element to vary its temperature and, therefore, its resistance to current flow.

Referring now more particularly to Figure 1 of the drawings for a more detailed description of the present invention, the receiver cell is shown as comprising a body portion In having a central conical chamber ll formed therein, the chamber being provided with a finely divided dark substance l2, such as carbonized vegetable fibres in the form of a fine fiufi'. Substance I2 is selected principally for its property to release stored or adsorbed gases when exposed to rays of radiant energy.

The open or flared end of chamber l l is closed by a window [3 formed of suitable material, such as, rock-salt, for example, while the interior of the chamber is placed in communication through a relatively narrow slot M with a chamber l5 defined by the rear of body portion l0 and a spacer element I6. A suitable casing l1 supports body portion I0 as well as element l6 therein while a retaining ring I8 is provided for closing the open end of the casing and for maintaining window [3 in scalable relation with chamber H.

Arranged within chamber I5 and directly behind slot l4, as better shown in Figure 2, is a coil 19 anchored at one end to an insulator 28 and at its other end to an insulator 2!, the coil consisting of many turns of extremely fine wire rigidly connected between the two insulators. Suitable conductors 22 connected to coil H! are withdrawn to the outside of easing I! through insulated apertures 23.

Coil I 9 may constitute one leg of a Wheatstone bridge arrangement and as better shown in Fi ure 3 it is connected with a, second leg having a resistor 24, each leg being provided with a common mid-point 25 and outer taps '26 and 21, av

suitable source of current, such as, battery 28, for example, being connected across outer taps 26, 21. A second pair of resistors 29 and 39 are connected to taps 26 and 21 and are provided with a common mid-point 3 I, the two mid-points being connected to a galvanometer 32 by way of leads 33. Normally, the above-described circuit is balanced, however, as soon as the resistance of coil I9 is changed the circuit becomes unbalanced and a difierence in potential is developed across mid-points 25 and 3| which is registered by galvanometer 32.

As shown in the arrangement of Figure 3 the change in the resistance of coil 19 may be indicated directly by meter 32 or, if desired, the

change be introduced into a conventional am plifier followed by a suitable indicator. To this end, therefore, the arrangement of Figure i'isprovided wherein the leads 33 and galvanometer32 of Figure 3 are eliminated and in their stead the mid-points 25 and 3| are connected by means of conductors 3d and 35 with the input of a cone ventional vacuum tube amplifier 3B, the output of which is fed by way of leads 3'! to an indicator ambienttemperature byreason of the fact that current from battery 28 flows the coil. Cooling of coil .19 .by the-gases passing through slot I4 results in a change in its resistance so that the circuit is -no ,longer balanced -and a difference in .potentialfiisdeveloped across mid-points 25 and 3] which may be either registered directly upon meter 32 of Figure 3=or fed into amplifier 36 to actuate theindicatortfi of Figure 4.

The heat capacity of coil 19 is verylow due to the extremely small wire diameter and, therefore, the resistance changes occur rapidly. The response of the cell to outside mechanical vibrations is practically eliminated because it does not depend upon any mechanical movement for Furthermore, .the sensitivity may be also increased by selecting wire for the soil whichposses-ses a high temperature *coefficient of resistance;

I-t willnow be apparent to those skilled in the art thata novel radiant energy receiver cell has been provided which is accurate and reliable V in performance and one which remains substantially unaffected by mechanical vibrations .resul-tingfrom accelerations or shocks imposed upon the celL ,4. V understood by those skilled'in the art. For a definition of the limits of the invention, reference will be had primarily to the appended claims.

Iclaim: 1. Radiant energy receiving apparatus com-- prising an electrical circuit having a conductor whose resistancevaries in accordance with a change in the temperature ,thereoi, a source of current in said circuit for providing current flow in said conductor to raise the temperature thereof relative to ambient temperatures, and means responsive to radiant energy for causing a gas to :fiow for cooling said conductor to thereby vary the resistance thereof;

ZQRadiant energy receiving apparatus comprising an electrical circuit having a conductor whose resistance varies in accordance with a change in the temperature thereof, gas adsorbing means-responsive to radiant energy for causing gas flow to impinge upon said conductor to vary the temperature thereof, and a source of current in said circuit for providing current flow in said conductor to raise the-temperature thereof relative to ambient temperatures.

3. Radiant energy receiving, apparatus comprising a normally balanced electrical circuit having a conductor whose resistance varies in accordance with a change in the temperature thereof, means responsive to radiant energy vfor causing a gas to flow to vary the temperature of said conductor whereby said circuit becomes unbalanced, a source of current in said circuit for providing current. flow in said conductor to raise the temperature thereof relative to ambient temperatures; and an indicator connected to said circuit. V

l. Radiant energy receiving apparatus comprising a normally balanced electrical circuit'having-a conductor-whose resistance variesin accordance with .a change in the temperature -thereof, gas adsorbing means responsive to radiant energy for causing gas flow to impinge upon said 'conductor to vary the temperature thereof whereby said circuit becomes unbalanced, a .source of current in said circuit ror providing current flow in said conductorto raise the temperature thereof relative to ambient temperatures, an amplifier connected to said circuit, and an indicator connected'to said amplifier. V

5. Radiant energy receiving apparatus comprising a casing, an electrical circuit including a conductor mounted in said casing, the resistance of said conductor varying in accordance with a change in .the temperature thereof, a chamber within said casing, means communicating said chamber with said conductor, means within said raise the temperature Although but a single embodiment of the present invention has been illustrated and described in detail, .it is to be expressly understood that the-invention is not limited-thereto, Various changes-may be made in the design .and arrangement'oi .theparts without departing from the spirit and scope of the invention, as will now e chamber responsive to radiant energy for causing a gas to flow to vary theitemperature of said conductor, and a source of current in said circuit for providing current flow in said conductor to thereof relative to ambient temperatures. 6. Radiant energy receiving apparatus provided with a casing, means comprising a con varied, and a source of current, connected to said:

conductor for providing a current fiow'thereinto raise the temperature thereof relative to ambient temperatures.

7. Radiant energy receiving apparatus comprising an electrical circuit containing a coil of fine wire, the resistance of the coil varying in accordance with a change in the temperature thereof, means responsive to radiant energy for causing a gas to flow to vary the temperature of said coil, and a source of current in said circuit for providing current fiow in said wire to raise the temperature thereof relative to ambient temperatures.

8. Radiant energy receiving apparatus having a casing, means comprising a coil of fine wire mounted within said casing, the resistance of the coil varying in accordance with a change in the temperature thereof, a closed chamber within said casing, means defining a passage between said chamber and said conductor, gas adsorbing means within said chamber responsive to radiant energy for causing gas fiow through said passage to impinge upon said coil whereby the temperature thereof is varied, and a source of current connected to said wire for providing a current flow therein to raise the temperature thereof relative to ambient temperatures.

9. In combination, a Wheatstone bridge circuit having one leg thereof formed of means whose electrical resistance varies with a change in the temperature thereof, gas adsorbing material responsive to radiant energy for causing gas flow to impinge upon said means to vary the temperature thereof, and a source of current for said circuit providing current flow in said one leg to raise the temperature thereof relative to ambient temperatures.

10. In combination, a Wheatstone bridge circuit having one leg thereof formed of means whose electrical resistance varies with a change in the temperature thereof whereby a difference in potential is developed across two points of said circuit, an indicator connected to said circuit and responsive to said difference in potential, means responsive to radiant energy for causing a gas to flow to vary the temperature of said firstnamed means, and a source of current connected to said circuit providing current flow in said one leg to raise the temperature thereof relative to ambient temperatures.

11. In combination, a Wheatstone bridge circuit having one leg thereof formed of means whose electrical resistance varies with a change in the temperature thereof whereby a difference in potential is developed across two points of said circuit, an amplifier connected to said circuit across said two points, an indicator connected to said amplifier and responsive to said diflerence in potential, means responsive to radiant energy for causing a gas to flow to vary the temperature of said first-named means, and a source of current connected to sai circuit providing current flow in said one leg to raise the temperature thereof relative to ambient temperatures.

12. In combination, a, Wheatstone bridge circuit, a coil of fine wire comprising one leg of said circuit, the electrical resistance of said coil varying with a change in the temperature thereof whereby a difference in potential is developed across two points of said circuit, means connected to said circuit and responsve to said difference in potential, means responsive to radiant energy for causing a gas to flow to vary the temperature of said coil, and a source of current in said circuit for providin current flow in said wire to raise the temperature thereof relative to ambient temperatures.

13. In combination with a casing, a Wheatstone bridge circuit, a coil of fine wire comprising one leg of sad circuit and mounted within said casing, the electrical resistance of said coil varying with a change in the temperature thereof whereby a difference in potential is developed across two points of said circuit, a closed chamber within said casing, means defining a passage between said chamber and said coil, gas adsorbing means within said chamber responsive to radiant energy for causing gas to flow through said passage tc impinge upon said coil whereby the temperature thereof is varied, a source of current in said circuit for providing current flow in said wire to raise the temperature thereof relative to ambient temperatures, and means connected to said circuit and responsive to said difierence in potential.

WILLIAM R. POLYE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,107,438 Moskowitz Aug. 18, 1914 1,229,740 Furstenau June 12, 1917 1,776,901 Essex et al Sept. 30, 1930 1,963,185 Wilson June 19, 1934 2,349,715 Francis May 23, 1944 2,352,377 Francis June 27, 1944 

